With the popularization of communication, telephone has become a necessary communication tool for people's daily life. While bringing convenience to people's lives, the phone also bring a lot of trouble. In particular, all kinds of harassing phone calls such as marketing, advertising and fraud have become increasingly rampant and seriously disturb people's daily lives. At the same time, more and more people are accustomed to using the software on the communication terminal such as cell phones for settlement of funds. Once the information is leaked, the resulting loss will be difficult to restore.
Therefore, it has become an urgent technical problem to be solved in the field of communications that how to prevent users from interfering with harassing phone calls without affecting the important incoming calls.